A typical ski turn can be described as a collection of decision points starting with the point at which the skier decides to begin the turn. A cascade of other decisions and actions follow, all of them dependent on when that first decision was made.
To properly initiate a ski turn, varying degrees of forward pressure are exerted against the tongue of the ski boot. For example, in one common turn in ski racing, the skier first exerts neutral forward pressure, followed by increasing continual forward pressure in varying degrees. Proper timing and maintenance of forward pressure can, depending on skiing conditions, improve the shape of the turn, the control of the turn, the speed of the skier, the direction of the turn, the quickness of edge transitions and many other nuances of a ski turn. These factors apply in varying degrees to varying ski conditions and circumstances such as recreational, racing, powder, groomed, ice, and bump (mogul) skiing as well as many other types of skiing and ski conditions. Teaching and training proper form with respect to ski turns is particularly difficult due both to difficulty in externally observing forward or other pressure and ski proximity and to an inability to communicate the form break to the skier at the moment the problem occurs.
One mechanical strategy of attempting to compensate for improper pressure distribution and ski proximity involves changing the physical shape of the skis. Shaping the ski often makes skiing easier but it does not of itself solve the full range of issues that result from improper pressure distribution and ski proximity. For example, in ski racing, if the skier is not generating sufficient forward pressure, a turn can be initiated but the racer can lose edge control, skidding and losing speed through the race course. This loss of control in one turn can cause further loss of control in one or more subsequent turns and even complete loss of control and exit from the race course. The difference between a correct turn and a bad turn is often a direct result of whether the skier is applying sufficient forward pressure to the portions of the ski boots abutting the skier's lower shin and whether the skis are appropriately spaced, or in some cases such as bump skiing not spaced, from one another.
Various electronic systems have been provided to try to provide real-time feedback to the skier. These systems have typically used small, spot electronic sensors selectively positioned by the skier. These systems have proven to be inaccurate due to their small size and inability to detect leg pressure across the surface of the tongue of the ski boot.
Additional disadvantages of the use of electronic spot sensors include the cost of electronic sensors, the use of multiple sensors to obtain accurate monitoring in a single ski boot, frequent adjustment to the location of the sensors within the boot in order to obtain the most accurate monitoring, and compromised durability due to susceptibility to weather conditions and friction.
Yet another disadvantage of these electronic systems is that they have not provided any detection of ski proximity. In certain types of skiing conditions and in ski racing in particular, the feet should be sufficiently independent, and the hips should not be locked in position with respect to the legs and feet. Further, when the feet are sufficiently separated from each other, the skier can generate edge pressure without tilting the body to one side. If a skier is notified only of pressure distribution without also being notified of ski proximity, the skier can only generate adequate forward pressure by tilting into the turn compromising balance and increasing the risk of falling. The applicants have discovered that, since ski proximity is such an important part of proper turn execution and other aspects of skiing, the lack of proximity monitoring results in an incomplete solution to the training challenges surrounding proper ski turns and other aspects of skiing.
Another disadvantage of prior electronic methods is that many have not associated each sensor with a specific limb and therefore have not indicated to the skier which leg was failing by, for example, exceeding a given pressure threshold. Further, the absence of independent, limb-associated sensors has prevented the skier from being able to adjust sensitivity independently for each sensor. This has resulted in failure to adequately report improper pressure for one of the two legs. Prior systems for monitoring skier lean have also typically employed uncomfortable or cumbersome mountings to the ski boot, the ankle, or a combination of both ski boot and ankle. Many of these systems have required semi-permanent to permanent positioning within the ski boot, making maintenance and location adjustment difficult.
Yet another issue is variability of ski boots and of the bones and tissue of the skier's shin. These variables have created even more difficulties with prior methods.